Math 220 Fall 2025 Written Homework 5 Due: October 15, 2025 Be sure to show all your work including each step of elimination and clearly indicate your final answer. On problems marked with [C], you may use a calculator or computer algebra system such as Mathematica or MatLab. On problems not marked with C, all work must be completed by hand. 1. Let A = 1 2 3 4 , B = 3 2 2 1 1 4 , and C = 1 2 3 4 5 6 7 8 10 . Perform each computation below or explain why the operation is undefined. (a) AB (b) BA (c) CBT (d) A2 (e) B2 (f) 2C T B (g) 3A1 (h) C 1 2. Let A, B, and C be n n invertible matrices. Simplify the expression as much as possible. Show all work for the simplification. B(C TAB1 ) 1 (BC) T (A TB 1 ) T 3. (a) Find the inverse of 1 4/5 2 7/5 . (b) Use your answer from (a) to solve the linear system